Koen Groeneveld (DJ Boozy Woozy) and Addy van der Zwan (Itty Bitty) first worked together in the Turn Up The Bass series of commercial mixes. They started producing music in the 1990s before meeting up with Jan Voermans (Greatski) in 1995. The trio created the sublabel Blue Records for parent Mid-Town Records to release their tracks as Klubbheads. In 1996, they had their first mainstream chart hit with "Klubbhopping", which reached #10 in the UK Singles Chart in May. It was followed up with two other entries in to the Top 40, in August 1997 with "Discohopping" (#35) and in August 1998 with "Kickin' Hard" (#36). In 1999 they co-produced "The Launch" for compatriot DJ Jean, reaching #2 in September...

Koen Groeneveld (DJ Boozy Woozy) and Addy van der Zwan (Itty Bitty) first worked together in the Turn Up The Bass series of commercial mixes. They started producing music in the 1990s before meeting up with Jan Voermans (Greatski) in 1995. The trio created the sublabel Blue Records for parent Mid-Town Records to release their tracks as Klubbheads. In 1996, they had their first mainstream chart hit with "Klubbhopping", which reached #10 in the UK Singles Chart in May. It was followed up with two other entries in to the Top 40, in August 1997 with "Discohopping" (#35) and in August 1998 with "Kickin' Hard" (#36). In 1999 they co-produced "The Launch" for compatriot DJ Jean, reaching #2 in September. At this time they also split up from Blue Records to found the label Digidance.
They scored a Billboard Hot Dance Airplay hit in 2003 with "E" (which samples Eminem's "Without Me") under the Drunkenmunky name. In other countries, it was released under the title "E (As In Eveline)" but the track didn't use the "Without Me" sampling. Their song "Yeah!" samples the crunk hit Yeah! by Usher to a similar success. In 2005 they sampled Rune RK's "Calabria" under the name Dirty Laundry. "Calabria" has been one of the most sampled songs used in the Dance community.
As Hi_Tack, they have released a remix of "Say Say Say" in 2006, a track originally by Paul McCartney and Michael Jackson (now renamed to "Say Say Say (Waiting 4 U)"), which reached #4 in the UK Singles Chart. The track entered the Billboard's Hot Dance Airplay chart in the United States, where it debuted at #18 for the week ending 6 March 2006. They have also remixed Filter Funk's cover of the Police song, "Message in a Bottle".
Voermans elected to end their partnership in the Spring of 2005 after ten years of collaboration". Groeneveld and van der Zwan continue to work together in a new label, Unit 54, while Voermans remains with Digidance.